//For Enrolment Controller
public void AddEnrolment(int StudentId, int CourseId)
{
Student student = _ctx.Students.Find(StudentId);
Course course = _ctx.Courses.Find(CourseId);
var newEnrol = new Enrolment {
StudentId = StudentId, CourseId = CourseId
};
_ctx.Enrolments.Add(newEnrol);
Save();
}